The present invention relates to a device for analyzing at least one analyte, comprising a container and a biochip, the latter being attached to the container by a suitable means of attachment.
The term “biochip” is intended to mean, and with reference to FIG. 1, any component comprising, in a way known per se, a support 9, in particular polyhedral in shape, for example parallelepipedal in shape. This support 9 comprises, firstly, an active face 3 comprising an active surface 31, onto which are distributed and attached a plurality of ligands 4 used for the analysis and, optionally, depending on the detection method used, a peripheral zone 32 free of ligands, secondly, at least one face 6 opposite the active face, for example parallel to the active face, and a transverse and peripheral strip 7, or edge, connecting the active 3 and opposite 6 faces, comprising, for example, several sides 71 to 74 in the case of a parallelepipedal shape.
Advantageously, the surface area of the active surface is less than 100 mm for example less than 65 mm2, and preferentially less than 30 mm2. The thickness of support, for example the width of the transverse strip 7, is less than 5 mm, advantageously less than 1 mm. In certain cases, the biochip support is in the shape of a cylindrical disk, in which case, the transverse strip has no edge.
Preferentially, the active surface represents at least 75% of the surface area of the active face.
The ligands may be attached in various ways, in particular by adsorption or covalence, such as for example in situ synthesis by photolithography techniques, or by a piezoelectric system, by capillary deposit of preformed ligands. By way of illustration, examples of these biochips are given in the publications by G. Ramsay, Nature Biotechnology, 16, p. 40–44, 1998; F. Ginot, Human Mutation, 10, p. 1–10, 1997; J. Cheng et al, Molecular diagnosis 1(3), p. 183–200, 1996; T. Livache et al, Nucleic Acids Research, 22(15), p. 2915–2921, 1994; J. Cheng et al, Nature Biotechnology, 16, p. 541–546, 1998, or in patents U.S. Pat. No. 4,981,783 (Augenlicht), U.S. Pat. No. 5,700,637 (Southern), U.S. Pat. No. 5,445,934 (Fodor), U.S. Pat. No. 5,744,305 (Fodor), U.S. Pat. No. 5,807,522 (Brown).
The state of the art consists of the document WO 95/33846, which describes a consumable for biological analysis, in which a biochip is attached to a plastic support. This parallelepipedal-shaped biochip comprises, on its active face, a large number, generally several thousands to several hundreds of thousands, of oligonucleotides placed at predetermined locations. Several means for attaching the biochip are described, both by adhesive bonding and by sealing. However, in all cases, part of the active face of the biochip, where the oligonucleotides are located, is used for the attachment to the plastic. In this case, the area on the active face used for attaching the biochip to the consumable is not available for oligonucleotides to be grafted onto it.
There are two constraints for the industrial application of these biochips. Firstly, the desire to reduce production costs for these biochips involves a decrease in the size of the latter, with, as an indirect consequence, a decrease in the size of the consumable, which decreases the costs of the device accordingly. Secondly, the desire to carry out several simultaneous analyses (such as detecting a panel of pathogenic agents in a biological sample, or detecting the effect of a molecule on the expression of a multitude of messenger RNAs in order to identify the metabolic pathway on which this molecule acts) with the same biochip leads to an increase in the number of ligands on the surface of the biochip. Thus, industrial logic deems that a maximum number of ligands be placed on a minimum surface area.
The technique described in application WO 95/33846 therefore has the major drawback of using part of the active face of the biochip for attaching it to a consumable, which is not compatible with the industrial constraints described above.
In addition, it is important that the optical detection should not be affected by the means of attachment.